1. BASE Jumping (sometimes written as B.A.S.E. jumping): BASE stands for Buildings, Antennae[天线], Spans[桥墩之间的一段桥梁] (bridges) and Earth (cliffs)—these being the fixed objects that masters of this incredibly dangerous sport jump from. BASE jumpers will jump with a parachute[降落伞] off any tall structure including skyscrapers, electrical towers, bridges and cliffs. In the past, BASE jumpers have leaped from the Golden Gate Bridge, the Eiffel Tower and the Empire State Building. People who try this sport almost always end up arrested (it's not exactly legal) and some don't even live long enough to get arrested. (We told you it was dangerous.)
2. Free Diving: Divers will plunge[跳进] up to 400 feet underwater in a single breath. At the 2001 Free Diving World Cup, 15 people had to be rescued because of blackouts[眩晕] caused by their brains not getting enough oxygen[氧气].
3. Cave Diving: Imagine being more than 100 feet underwater in a deep, cold and dark cave. Divers are well-trained but there are so many things that can go wrong which is why this is one of the world's most dangerous sports. You can lose your way, run out of air, your equipment can fail or you can be eaten alive by a cave creature.
4. Speed Skiing: This is the world's fastest non-motorized sport and one of the world's most dangerous sports.
Skiers wear special skis and aerodynamic[空气动力学的] suits to fly down a hill at speeds up to 160 miles per hour! That's almost as fast as a racecar! One crash often means death.
5. Rock Fishing: Unless you're a fish, how can fishing be one of the world's most dangerous sports? Rock fishing involves casting[投，抛] a line into the ocean from the shoreline.
People often forget about the tides and are swept away[一扫而空] or are dragged[拖曳] underwater by massive waves. In 2001, 15 people in Australia died while rock fishing.
6. Bull Riding: Jump on a raging[狂怒的] bull who hates your guts[勇气] and try to hang on. That's the game of bull riding. Some of the bulls weigh over 2000 pounds and can throw a rider off in a split second[瞬间]—and may even stomp[重踏] on the rider afterwards. Riders suffer broken bones, punctured[刺穿] lungs and even death.
7. Supercross: Athletes fly in the air on a motorcycle while doing backflips[后空翻], taking their hands off the handlebars and doing other death-defying stunts[特技].
8. Solo Yacht Racing: In a race around the world, sailors encounter waves, sharks, hurricanes and even pirates. The nearest help can be hundreds of miles away and racers have no control over the conditions they run into. With no one nearby to help them out, racers can lose the race and their lives.
9. Street Luging[坐在平底雪橇里滑雪]: Highly modified[改良的] skateboards are used to race down a hill at speeds of up to 80 miles per hour. The pioneers of this sport originally raced down hills in the middle of traffic which made it even more risky. There are now special luges and equipment for the sport which make it much safer. But hey, you're still hitting pavement when you crash.
10. Riding a Bike: We've all heard the phrase “it's as easy as riding a bike.” Well, riding a bike can still be dangerous. More kids break bones or dislocate[脱臼] joints riding bicycles than any other sport.